Anti-whaling activist Pete Bethune is developing a new multi-million dollar high-speed trimaran to replace the Ady Gil, which could be patrolling the world's waters chasing down poachers.
Mr Bethune, who spent four months in Japanese prison this year after taking part in a bitter anti-whaling protests in the Southern Ocean, which saw the Ady Gil sunk after colliding with a Japanese whaler, said he spent time in prison thinking about requirements for a vessel to work solely on marine conservation.
Mr Bethune built the biodiesel-powered Ady Gil, formerly known as Earthrace, and set a world record for a circumnavigation of the world in a power boat in 2008.
However, it was not ideal for conservation work and the new design would see a much bigger Ady Gil II - 40m to 45m long - carrying up to 20 crew and able to carry a 9m inflatable speedboat.
It could cost up to $US10 million, more than three times the original Earthrace.
It would have "a fair bit of Earthrace character in it'' in that it would be a tri-hull, but with the central accommodation area going out over the hulls, he said.
Mr Bethune has posted an image of the new boat on his Facebook page, although it would probably change in development.
He said it would "effectively be built as per the military pursuit boats", a much tougher vessel and be able to chase down poachers.
Mr Bethune had given his concept to Auckland naval architecture and yacht design firm Lomocean Design, the same designers who worked on Earthrace.
The new boat, which would probably be biodiesel-powered, could take six months to design and two years to build, which could see it launched in 2013.
Mr Bethune said such a boat, with the backing of local authorities, could make a real dent in poaching operations around the world, such as yellow fin tuna poachers around Fiji.
"There are many countries around the globe who know that their waters are being raped all the time and they are powerless to do anything.''
Mr Bethune said the boat would not operate under the Sea Shepherd banner - which ran the Southern Ocean protests and who he later fell out with - but he was looking for backers.
"At this stage I am just putting out the feelers to see, can I get a boat to meet these specs, what's it going to cost us to build and once I get those I'll look to see how we go funding it.''
Mr Bethune, who since returning from prison in Japan, has finished his book Whale Warrior, said the new boat would not break the rules of his suspended sentence in Japan.
However, he did admit to breaking one of the conditions of his sentence on Friday during worldwide anti whaling protests.
"I took two steps into the Japanese Embassy in Wellington at the protest and I am banned from Japanese soil for five years.
He said he had permission to deliver a petition and admitted he knew he was stepping on to Japanese soil.
"I did go breaking the thing but I don't think they were too fussed by it. They never mentioned it and I wasn't arrested.''